Most houseboats are well-equipped with heating so that won’t be much of a problem I think.
I can suggest getting a travelguide for Amsterdam but you could also just start walking around, for every interesting thing is pretty much concentrated in the centre of the city. On my visit to Rome I used this guide called ‘100% Rome’, and if I remember well there’s also a ‘100% Amsterdam’ version. It’s a little more hip and modern than conventional travelguides.
They say there are more english speaking people in Amsterdam than in New York, so don’t be afraid to ask people on the streets for things you need.